An interventional study of Inhalation Challenge with ATP and Inhalation Challenge with AMP in Asthma, COPD and Smoking, sponsored by Imperial College London. Completed at 1 site in United Kingdom. Open to participants aged 21 Years to 85 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-04-04.
Sponsored by Imperial College London · Not applicable and Interventional
In this randomised, cross-over, controlled study, a total of 84 subjects will be included: 12 healthy non-smoking volunteers; 12 current smokers; 30 patients with mild steroid-naïve asthma; and 30 patients with mild-moderate COPD.
Each subject will have 1 screening visit (if necessary) and 2 study visits. At visits 2 and 3 the effects of adenosine 5'-triphosphate (ATP) or adenosine 5'-monophosphate (AMP) challenge, given in a random order, will be tested.
Background: Extracellular adenosine 5'-triphosphate (ATP) stimulates vagal C and Aδ fibers in the lung, resulting in pronounced bronchoconstriction and cough mediated by P2X2/3 receptors located on vagal sensory nerve terminals. We investigated the effects of nebulized ATP on cough and symptoms in control subjects, healthy smokers, and patients with COPD and compared these responses to the effects of inhaled adenosine, the metabolite of ATP.
Methods: We studied the effects of inhaled ATP and adenosine monophosphate (AMP) on airway caliber, perception of dyspnea assessed by the Borg score, cough sensitivity, and ATP in exhaled breath condensate in healthy nonsmokers (n = 10), healthy smokers (n = 14), and patients with COPD (n = 7).
Results: In comparison with healthy subjects, ATP induced more dyspnea, cough, and throat irritation in smokers and patients with COPD, and the effects of ATP were more pronounced than those of AMP. The concentration of ATP in the exhaled breath condensate of patients with COPD was elevated compared with that of healthy subjects.
Conclusions: Smokers and patients with COPD manifest hypersensitivity to extracellular ATP, which may play a mechanistic role in COPD.
4,010 studies on the registry are indexed under Asthma; 514 are open to participants now.
This study's enrollment of 31 is below the median of 83 across 2,814 interventional studies indexed under Asthma.
Browse Asthma studies →Imperial College London is the lead sponsor of 842 studies on the registry; 180 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
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Healthy non-smokers (n=12)
At risk (current smokers) (n=12)*
Mild steroid-naïve asthma (n=30)
Mild-moderate COPD (n=30)
Exclusion Criteria:
Procedure: Inhalation Challenge with ATP · Procedure: Inhalation Challenge with AMP
Procedure: Inhalation Challenge with ATP · Procedure: Inhalation Challenge with AMP
PC20 of ATP and AMP
PC20 of ATP and AMP
Time frame: On administration
Lung function
Spirometry
Time frame: On administration
Borg score
Measurement of DYSPNEA
Time frame: On administration
Impulse oscillometry (IOS)
Small airway function
Time frame: On administration
Ran from Oct 2002 to primary completion in Oct 2004, 24 months.
Of 466 non-industry interventional studies with no phase under Asthma, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 47. This study's 24 months is close to that.
Counting every sponsor, half of 502 studies reached it within 23 months; a quarter within 10 and three quarters within 46.
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This study is completed, as verified in Apr 2024. You cannot join it, but the record below documents what was studied.
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